C57BL/6N mice, an important strain in several NIEHS studies, develop an alopecia which usually arises at 4 to 6 months of age. This condition often progresses into a protracted dermatitis and may become severe enough that the animals develop ulcerative skin lesions and suffer premature morbidity and mortality. We have initiated a project directed at discovering a nutritional basis for the progressive skin disorders. In a one-year pilot study, mice were divided into groups of 15 and fed either the standard NIH-31 diet (control diet) or a test diet made by fortifying the NIH-31 diet with vegetable oils, animal fat, thiamine, riboflavin, pyridoxine, cyanocobalamin, biotin, zinc oxide, or other vitamin and mineral mixtures. Obvious clinical differences were observed between groups and the alopecia and degenerative skin conditions were reduced or improved by combinations of the vitamin and mineral mixtures. These preliminary findings suggest that C57BL/6N mice may require dietary changes as they age to compensate for natural degenerative skin changes that occur, probably due to strain dependent genetic predisposition. A second study is underway to confirm these findings and hopefully provide additional information on the role of specific minerals/vitamins, etc,.. in preventing or inducing the alopecia, ulcerative skin lesions observed in C57BL/6N mice. The second study has been underway for eight months. Groups of mice will continue to be evaluated for at least one year and the results will be compared to the previous study.